1. Field of the Invention
The present invention relates to a method for manufacturing a substrate provided with a semiconductor layer with an insulating film interposed therebetween, and especially, a method for manufacturing an SOI (silicon on insulator) substrate. In addition, the present invention relates to a method for manufacturing a semiconductor device using a substrate provided with a semiconductor layer with an insulating film interposed therebetween.
2. Description of the Related Art
In recent years, an integrated circuit using an SOI (silicon on insulator) substrate in which a thin single crystal semiconductor layer is formed over an insulating surface, instead of using a bulk silicon wafer, has been developed. Since parasitic capacitance between a drain of a transistor and a substrate is reduced by using the SOI substrate, the SOI substrate has attracted attention as one improving performance of a semiconductor integrated circuit.
A Smart Cut (registered trademark) method is known as one of methods for manufacturing an SOI substrate (for example, see Patent Document 1). An outline of a method for manufacturing an SOI substrate by a Smart Cut (registered trademark) method is described below. First, hydrogen ions are implanted into a silicon wafer by an ion implantation method, so that an embrittlement region is formed at a predetermined depth from a surface. Then, the silicon wafer into which the hydrogen ions are implanted is bonded to another silicon wafer with a silicon oxide film interposed therebetween. Then, by heat treatment, part of the silicon wafer into which hydrogen ions have been implanted is separated in a thin film shape along the embrittlement region which serves as a cleavage plane; accordingly, a single crystal silicon film can be formed over the other silicon wafer that has been bonded. A Smart Cut (registered trademark) method is also referred to as a hydrogen ion implantation separation method.